Camera viewing systems are utilized in abundance for surveillance, inspection, security, and remote sensing. Remote viewing is critical for robotic manipulation tasks. Close viewing is necessary for detailed manipulation tasks while wide-angle viewing aids positioning of the robotic system to avoid collisions with the work space. The majority of these systems use either a fixed-mount camera with a limited viewing field, or they utilize mechanical pan-and-tilt platforms and mechanized zoom lenses to orient the camera and magnify its image. In the applications where orientation of the camera and magnification of its image are required, the mechanical solution is large and can subtend a significant volume making the viewing system difficult to conceal or use in close quarters. Several cameras are usually necessary to provide wide-angle viewing of the work space.
In order to provide a maximum amount of viewing coverage or subtended angle, mechanical pan/tilt mechanisms usually use motorized drives and gear mechanisms to manipulate the vertical and horizontal orientation. An example of such a device is shown in U.S. Pat. No. 4,728,839 issued to J. B. Coughlan, et al, on Mar. 1, 1988. Collisions with the working environment caused by these mechanical pan/tilt orientation mechanisms can damage both the camera and the work space and impede the remote handling operation. Simultaneously, viewing in said remote environments is extremely important to the performance of inspection and manipulation activities.
Camera viewing systems that use internal optics to provide wide viewing angles have also been developed in order to minimize the size and volume of the camera and the intrusion into the viewing area. These systems rely on the movement of either a mirror or prism to change the tilt-angle of orientation and provide mechanical rotation of the entire camera to change the pitch angle of orientation. Using this means, the size of the camera orientation system can be minimized, but "blind spots" in the center of the view result. Also, these systems typically have no means of magnifying the image and or producing multiple images from a single camera.
Accordingly, it is an object of the present invention to provide an apparatus that can provide an image of any portion of the viewing space within a hemispherical field-of-view without moving the apparatus.
It is another object of the present invention to provide horizontal orientation (pan) of the viewing direction with no moving mechanisms.
It is another object of the present invention to provide vertical orientation (tilt) of the viewing direction with no moving mechanisms.
It is another object of the present invention to provide rotational orientation (rotation) of the viewing direction with no moving mechanisms.
It is another object of the present invention to provide the ability to magnify or scale the image (zoom in and out) electronically.
It is another object of the present invention to provide electronic control of the image intensity (iris level).
It is another object of the present invention to be able to change the image intensity (iris level) without any mechanisms.
It is another object of the present invention to be able to accomplish said pan, tilt, zoom, rotation, and iris with simple inputs made by a lay person from a joystick, keyboard controller, or computer controlled means.
It is also an object of the present invention to provide accurate control of the absolute viewing direction and orientations using said input devices.
A further object of the present invention is to provide the ability to produce multiple images with different orientations and magnifications simultaneously.
Another object of the present invention is to be able to provide these images at real-time video rates, that is 30 transformed images per second, and to support various display format standards such as the National Television Standards Committee RS-170 display format.
These and other objects of the present invention will become apparent upon consideration of the drawings hereinafter in combination with a complete description thereof.